


A Fell Attraction

by PurrfecktlySinful



Category: Undertale (Video Game)
Genre: Angst, Choking, Ecto-Penis (Undertale), Ecto-Tongue (Undertale), Fellcest - Freeform, First Time Together, Fontcest, Frottage, Guilt, M/M, Sibling Incest, Sloppy Makeouts, Suicidal Thoughts, and Papyrus just goes after what he wants, in a very non sexual way, where Sans overthinks things
Language: English
Status: Completed
Published: 2019-06-02
Updated: 2019-06-02
Packaged: 2020-04-06 10:28:34
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 5,070
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/19060807
Author URL: https://archiveofourown.org/users/PurrfecktlySinful/pseuds/PurrfecktlySinful
Summary: Guilty Fellcest, given to me by an anonymous commissioner.And yup. Still here. Still writing. Hopefully I'll be able to update my normal fics soon.





	A Fell Attraction

They’re brothers.

For fuck’s sake, Sans could still remember when Papyrus was smaller than him, all bright eyes, hope and wonder when “Santa Claus” left a scuffed, beat up action figure next to his pillow on Gyftmas Eve. It was the only halfway decent toy Sans could scrounge up at the dump. It had been missing an arm, but Papyrus had only claimed that it must mean that the other arm “MUST BE EXTRA SUPER STRONG, SANS. LOOK AT HIM! ISN’T HE COOL!”

“heh. yeah bro, the coolest.”

He still remembered the grief as he had watched the fucked world twist that optimism, changing it from wide-eyed belief that there was good everywhere into a dogged determination to excel at everything he did, even if that ‘everything’ was brutally dusting any monster that so much as spit in their direction.

Then there had been the rage when an unexpected lucky shot had cracked Papyrus’ skull (even Papyrus had looked shocked as Sans had relentlessly chased the fucker down to finish him off), and the gut-sick, worried days afterward as Sans had nursed his little brother back to health.

Lastly there was the pride. Stars DAMN, Sans had so much pride in Papyrus that there were times at which he felt his soul might burst with it. His brother was efficient, calculating, whip-smart in battle and had pinpoint control over his magic. He had no trouble joining the Royal Guard under its current captain, Undyne, and was now her right-hand monster. It had finally gotten to the point where, when Papyrus had begun to not-so-subtly take charge in most of the family decisions, Sans had simply stepped back and let him, only needling back by starting to call him ‘Boss’. Papyrus, unflappable as always, merely accepted the term of endearment for what it was, only the faintest of blushes to betray otherwise.

After all, Sans figured, ANY way had to be better than the shitshow he had been running since they were kids. Migrating from place to place, only barely managing to find food, clothing and shelter. There were times Sans had to do some fairly underhanded shit just to keep them alive. He was sure Papyrus could do much better without having to cope with Sans’ personal failures complicating his life, so he backed off and changed his focus to a more supporting role, the one he’d had up till then. 

Pride, love, protectiveness. These were all emotions that he was SUPPOSED to have toward his little brother. 

But Sans should have known that he was gonna fuck that up as well. 

It started small. A subtle appreciation as Papyrus came into adulthood of how fine a monster he was. Straight and tall, his bearing commanding and his gaze full of grim confidence, Papyrus was the epitome of what any other monster would find attractive. It wouldn’t surprise Sans at all if Papyrus found a partner quickly, even if the thought of it sounded a small, painful pang deep within his soul.

But then one day he caught his own gaze lingering, without thought, along the curve of his brother’s spine to rest on the twin iliac crests peeking up above the low-cut leather pants his brother always wore. It was a few moments before he could pull his gaze away, a confused, heated feeling rising up within him. What the fuck was that?

“SANS! WHAT IS WRONG WITH YOU?” Papyrus’ voice sliced through his thoughts, bringing him out of his internal examination of himself.

Sans jumped at the question, suddenly awash with the chill feeling of guilt. Oh stars, had Papyrus seen that? What would he think of his own brother ogling him like he was some fuckable piece of tailbone?

“wha-? Boss? i mean, i…” he fumbled, looking for some excuse to explain it away.

Papyrus cut him off before he could continue.

“YOU REALLY NEED TO LEARN TO PAY ATTENTION, BROTHER! WHAT IF SOMEONE DECIDED TO TAKE ADVANTAGE OF US WHILE YOU WERE SPACING OUT LIKE THAT?” 

Relief caused the tension to drain from Sans’ shoulders. 

“yeah. you’re right, Boss. it’s a good thing I got the Great and Terrible Papyrus to keep a socket out for me.” He grinned at his brother and tipped him a wink. 

Papyrus faltered for a moment, a faint dusting of red making its way across his cheekbones. Sans chuckled inwardly as he watched his brother fluster, and then preen at the compliment.

“YES. WELL… OF COURSE! SOMEONE HAS TO KEEP AN EYE OUT FOR YOU, LAZYBONES.” Papyrus straightened, putting his hands on his hips. “JUST PAY MORE ATTENTION IN THE FUTURE.”

“got it, Boss.” 

The moment was forgotten until some weeks later. It had been a stressful day, and Sans had decided that the best way to release (heh) some steam was to crank one out before bed. No biggie, he’d jerked off many a time before. One of his many talents was his ability to recall a large mental catalog of wank material. For example, those had been some nice, tight pants Grillbz had been wearing today…

He took his time, conjuring up a delicious scenario in his mind. He was drinking late at the bar, watching Grillby clean up at the end of the night. Suddenly, the flame elemental had sidled up behind him, pressing into him from behind. He could imagine how the bulge of Grillby’s erection would feel as it nudged at him and how the bar owner’s warm hands would slide up under his jacket, then his shirt to tease at his ribs for a bit before one of them would make its way down into his pants, where Sans’ cock has already formed, aching for attention.

Sans ran a hand up and down his shaft, allowing his precome to smooth the way for him… long, slow strokes, allowing the pleasure to build gradually, imagining all the dirty things Grillby would whisper into his ear. 

Fuck he was close now, his strokes becoming quicker, more insistent, his hips bucking lightly into his hand as he chased his pleasure to it’s inevitable conclusion. In his fantasy, he imagined the warm body behind him grinding into him, pressing him hard into the bar counter. The whole time that hot palm would never leave his cock. 

…And finally, he imagined a voice, low and husky, breathe into his ear.

“YES, SANS. COME FOR ME, BROTHER.”

Sans’ hips stuttered and jerked as he came, a startled cry escaping his mouth despite his best efforts to remain quiet. Hot, wet cum spurted over his hand and onto the sheets beneath him.

Sans breathed for a few moments, his mind blessedly blank, his body lax against the mattress and curled around the mess he had made. The coolness of the pillow felt good pressed against his heated face as he panted into it, his mind beginning to collect itself as he came down. 

FUCK.

Sans felt his soul give a sudden clench. Had he really just imagined his fucking BROTHER into one of his sex fantasies? Holy shit, how fucked up was he, really? The gears in his mind worked feverishly as he put together the pieces. How recently his eyes had been drawn to the tall, lithe form of his brother, watching his movements as though entranced. How he enjoyed simply being in his presence, watching him do everything he did so well and bathing in the commanding aura he radiated no matter where he went. Slowly, Sans pulled back the veneer of his own dishonesty, evaluating his honest to stars feelings in those moments. 

Ooooohhh shit.

Those sure as hell weren’t brotherly feelings. Fuck, fuck, fuck.

Guilt churned in his gut, making him feel queasy. Their world was a violent shit-hole, full of backstabbing assholes whose way of saying ‘Have a nice day’ was sticking a knife between your ribs, but this? This was depraved. This was wrong. 

It was as though the one pure happiness in Sans’ life was suddenly poisoned by his own desires. Of course he had only himself to blame for this. He had known for a long time what kind of monster he was, and should have known that he would eventually drag his amazing brother into the same mire, either intentionally or not. 

He didn’t sleep at all that night, alternating between staring at the slowly drying cum on his blankets with what felt like a hole in his soul, and thinking feverishly of some way to fix it, to resolve this sudden, disgusting aberration of a problem that he could no longer ignore. 

By the time morning came, he decided to take the same course of action he did with all of his other problems.

Avoidance. 

He began to make excuses. Excuses to leave the house after Papyrus had gone off to his duties. Excuses to isolate himself when home. He became a shadow in his own home, sneaking to the kitchen in the small hours of the night when Papyrus slept to feed himself. Shutting himself in his room the rest of the time and ignoring his brother’s calls to “GET YOUR LAZY ASS OUT OF BED!”. When he went to his varied odd jobs, he took a shortcut, and when returning home, rather than wait for his brother to pick him up (which he inevitably would do without fail) he would leave a few minutes -or hours- early, either taking another shortcut or walking one of the other secluded side trails he had discovered while scouting the area out. Even when he couldn’t avoid his brother he kept the interactions short, saying only whatever was necessary to get away. 

Each time, it seemed as though Papyrus had been on the verge of stopping him, of saying something more about the sudden shift in Sans’ behavior, but he would abruptly clamp his mouth shut, accepting Sans’ bullshit of the moment with an unusually restrained stoicism. And since Sans knew his brother well enough to catch the veiled hurt in his eyes, his guilt and self-loathing only deepened. 

After one particularly long work shift, Sans decided that, rather than take a shortcut home, he would use one of the lesser-known, winding side-paths to get back to town. He sorely needed to clear his head and soothe some of the tightly wound anxiety that had been building within him, placing him precariously on edge whenever his brother was present. It was obvious to him that Papyrus knew something was off, and that he could only avoid his more determined younger brother for so long. Yet he was still at a loss for what to do. 

He never heard the monster sneaking up on him. 

They hit him hard and fast, bowling him end over end, both of them rolling in the snow until they came to a stop with Sans’ assailant pinning him.

Murderous, feral eyes glared at him from a face framed by dirty, matted gray fur. Despite the signs of starvation evident by the ribs visible through his unkempt coat, the other monster was still terribly strong, the hand around Sans’ throat squeezing painfully tight. 

Memory flashed through the panic. Something about Ice Wolf succumbing to his high LV, killing a member of the rabbit clan, then escaping into the surrounding woods. The Royal Guard had been positive that he had died of hunger, exposure, or both. 

Apparently not. 

“hhey buddy…” Sans managed to choke out, trying to quell his panic. “just chill ouuhhhhkkg-”

The hand around his throat tightened further, the wolf’s sharp claws pressing dangerously into Sans’ cervical vertebrae. 

“Shut up, bone man,” he growled. “I don’t like it when my dinner talks back.”

Oh fuck. Would that even work? Would his dust even have enough magic in it to sustain the other monster? 

He could see from the mad gleam in the wolf’s eyes that it really didn’t matter one way or another. 

Welp. This would be a solution to his problem, now, wouldn’t it?

As the thought flashed through his mind, a strange calm fell over him, the certainty of his death and the ultimate benefit of such to his brother becoming startlingly clear.

But if this fucker was gonna take him out, he sure as shit wasn’t gonna go alone. He grinned manically up at the mutt, his eye lights becoming sharp, glittering rubies in his sockets. Sans gathered his magic and from somewhere above them came the high-pitched whine of concentrated magic as he summoned a blaster. However, despite being half-starved and totally bat-shit crazy, Ice Wolf hadn’t lost the monster instinct for survival. Sans saw the other monster’s eyes widen in realization, followed by the resolve to end Sans then and there. 

Sans wasn’t going to be able to stop Ice Wolf from killing him, but they both knew that he wouldn’t be in time to stop the blaster, either.

“ffugkk… hyyouhh…” Sans gasped, eagerly counting the seconds to his death.

A sudden jarring blow slammed into Ice Wolf hard, knocking him off Sans and across the snow until he hit the trunk of a large tree with a resounding crash. 

Sans blinked, the resonating whine of his blaster cutting off abruptly as he tried to reassess the situation… Until a face appeared above him, familiar cracked face and red eye lights glaring down at him.

“wha… Boss? how…?” Sans sputtered.

“SHUT THE FUCK UP, SANS, AND GET US THE HELL OUT OF HERE,” Papyrus snapped in command, glancing up at Ice Wolf, who was already groaning and struggling to orient himself. 

Sans didn’t need to be asked twice where his brother was involved. Grabbing tightly onto Papyrus’ shoulder, he took the first shortcut that came within reach.

They both thumped onto a soft surface, Papyrus sprawled heavily over Sans, Sans still clutching for dear life at Papyrus’ arm. 

It was only a few breaths before Papyrus was up, propped on his arms over Sans protectively, scanning the area around them for any threats. 

“…s ok,” Sans croaked. “…your room.”

The tension visibly drained from Papyrus’ shoulders when he realized that Sans was right. The lighting was dim, but they could make out the faint shapes of Papyrus’ pirate flag and the small table with his collection of “tactical figurines” next to the bed, the one in the center conspicuously missing an arm. 

Suddenly struck by their position and how close Papyrus was to him, Sans’ soul began to race. He swallowed nervously, trying to distract his mind and his magic from the situation by reciting physics formulae in his head. 

To his relief, Papyrus moved from Sans, getting up to glare down at him with his hands on his hips. 

Shit. Sans knew that look. Papyrus was PISSED. He could see the rage smoldering in his expression, even in the low light. 

After glaring for a few more moments, Papyrus whirled on his heels, hands clenched, and strode purposefully to the door. 

Giving a quiet sigh, Sans began to scramble off the bed to get while the getting was good. 

The light snapped on and Papyrus turned, pinning Sans in place with his expression.

“DON’T. MOVE,” he said, his voice low and dangerous. 

Sans didn’t move, plunking back down on the bed obediently at the order. He knew better than to argue with Papyrus when he was like this. His emotional comfort wasn’t worth a couple of broken limbs. 

A few moments later, Papyrus was back with a small basin and a cloth.

“STRIP.”

“uh, nah, Boss i can handle it if you just let me have…”

“STRIP BEFORE I TEAR THOSE CLOTHES OFF YOU MYSELF!” he barked.

Sans felt a shiver run down his spine at the threat, his traitorous mind imagining exactly how much he would like Papyrus to do exactly that before he viciously smashed the thought back down. As though to prove to himself that it really was no big deal to undress in front of his own brother for fuck’s sake, Sans stood and began to slowly strip off his outer clothes. 

As he was pulling his shirt off over his head he caught sight of Papyrus staring at him, his gaze intense and unwavering. Taken aback a bit, Sans shuffled from one foot to the next for a moment before grumbling. 

“take a picture, it’ll last longer.” 

Papyrus blinked as though remembering himself, before turning his eyes to the side and crossing his arms.

“JUST HURRY UP.”

Sans turned his back to his brother in an attempt to forget he was just… right THERE as he was undressing. Despite this, he could still feel the heat of Papyrus’ gaze on his back, and Sans’ control on his magic was beginning to wear thin. 

After undressing down to his boxers, Sans turned around, threw himself back down on the edge of Papyrus’ bed and crossed his own arms over his chest.

“there, asshole. ya happy?”

“YES.” Papyrus’ answer was clipped as he knelt down and set the bowl next to him. Taking Sans by the wrist, he gently pulled the arm forward and began to methodically examine every inch of Sans’ body, checking for injury. 

Each touch was torture. While Papyrus was still visibly angry, his hands were careful, almost gentle as he moved up his arm, paying attention to each bit of exposed bone. Hands, wrists, joints, ribs… it felt like every iota of Sans’ magic was primed, trying to anticipate where his brother’s strong, graceful fingers would move next, manipulating, carefully inspecting.

When Papyrus finally reached the obvious injury at Sans’ neck, his expression deepened into grim concentration. 

“TIP YOUR HEAD BACK.”

Too focused on trying to keep his roiling magic in check, Sans obeyed without so much as a single quip. Papyrus dipped the cloth in the warm water at his side and wiped at his neck. Sans could see from the bottom of his eye sockets that the cloth was stained with red magic when Papyrus drew it away. He hadn’t even known that he’d been bleeding. 

He concentrated on keeping his breathing steady, trying not to think of how much this felt like he was baring his neck… submitting to his brother’s touch… allowing Papyrus to do whatever he wanted. Would Papyrus be the type to caress? To nibble? Or maybe something more forceful?

“FROM NOW ON, DO NOT LEAVE YOUR POST TILL I COME TO GET YOU.”

Sans jumped when his brother spoke, thoughts pulled suddenly from the slippery slope they were beginning to slide down. It took a moment for him to gather his wits, his eyes turned down to track Papyrus as he returned the cloth to the bowl. Fighting the shame within him, he searched for a response as he watched his own magic seep out of the cloth into the tepid water, staining it with clouds of red. 

He gave Papyrus a strained smile.

“aw, bro. i woulda been fine. you saw i’d have blasted—”

“SANS. EXCUSE ME FOR SAYING I DON’T GIVE A GOOD STARS DAMN WHAT YOU WOULD HAVE DONE. YOU WILL DO WHAT I ASK IN THIS MATTER. NOW SIT STILL.”

He sensed it as Papyrus placed a hand near his throat, and Sans felt the faint sputter of his brother’s healing magic as it began to flow into the scratched, bruised vertebrae, gradually soothing away the pain. Papyrus’ ability to heal used to be much stronger when he was younger… more hopeful… But even now he controlled it with the same pinpoint precision that made Sans proud. It wouldn’t be long before the last vestiges of his injury had faded to nothing. 

Sans closed his eyes, sighing with relief as he felt the comforting, familiar feel of his brother’s magic finish its work. The last of the discomfort dulled and disappeared. So effective were the results that Sans was entirely unprepared when Papyrus closed the gap between his hand and Sans’ neck, running a thumb over the sensitive bone there, satisfied that the healing was complete. 

Sharply, audibly, Sans breathed in at the jolt of pleasure that traveled down his spine from that touch, his magic breaking free from his control and settling suddenly and heavily in his pelvis. Papyrus’ eyes shot up to meet Sans’ and instinctively Sans retreated, backing over the bed like a startled animal, eyes wide with alarm.. 

Papyrus, however, was quicker than Sans. His hand shot out, grabbing Sans by the upper arm, trying to halt the smaller monster’s retreat. What he hadn’t planned for was the sturdy strength Sans could muster when he was serious. The result of the tussle was that Papyrus stumbled precariously out of balance and was then yanked out of his lunge and into an undignified flop on top of his older brother.

Sputtering, Papyrus pushed himself up, looking down at Sans in shocked indignation.

“FUCK! WHAT THE HELL IS WRONG WITH YOU SANS!? DID I HURT—” 

The question petered out. Sans saw his brother staring down at him, face now dangerously neutral. More precisely, he was looking straight at the now very obvious glow in Sans’ shorts. 

“y-you can… uh… just ignore that. it’s… ah… my um… magic is acting up... i’ll just go and…” Sans, simultaneously cold with mortification and hot with arousal, tried to roll out from under Papyrus to get away. He would go to his room, take care of his little problem and then very definitely never come out again. 

He was abruptly flipped back over on his back and pressed into the mattress by one of Papyrus’ hands on his shoulder, his only escape now removed from him as he was securely pinned. 

Papyrus stared at Sans for what felt like an eternity. Sans felt as though his brother’s gaze were methodically picking him apart, pulling bone from bone and thought from thought, seeing into every disgraceful and disgusting desire in his soul. 

Ashamed and afraid, Sans began to tremble.

“THIS IS WHY YOU’VE BEEN AVOIDING ME.”

Not a question. A statement.

This was it. This was the moment Sans lost everything. He felt a familiar numbness sweep over him. 

Schooling his face into cold passivity, Sans looked levelly back up at Papyrus.

“yeah. now you know. but you don’t have to worry. i’ll leave and you never have to see me—” 

Sans yelped as Papyrus gave him a hard, skull-rattling shake, causing him to rebound a bit against the mattress.

“DON’T.”

“but Boss, i can’t—”

Another shake, and Sans could now see that Papyrus was glowering down at him with a burning look in his eye sockets.

“I. SAID. DON’T!” The words were sharp staccato, as though Papyrus were fighting to push each word out through clenched teeth.

Sans fell silent. Another few moments passed. He could feel the bite of Papyrus’ fingers in his shoulder and the pressure of the mattress against his back where he was pressed down into it. He couldn’t move, and Papyrus wouldn’t let him speak. Now what?

Papyrus took a deep breath. 

“WHY? WHY TRY TO GET YOURSELF KILLED?”

Sans looked away.

The grip on his shoulder tightened. 

“I DESERVE AN ANSWER SANS! TELL ME!”

“because i’m a disgusting freak who wants to fuck his brother!” Sans snapped, suddenly angry “there! i said it. now let me the fuck go and i’ll get out of your space!”

“YOU DO NOT GET TO DECIDE WHO I WANT IN MY SPACE!” 

Sans laughed bitterly, his teeth turning up in a sardonic grin.

“oh. right. like you really want a gross, deviant, brother fucker like me hanging around. why don’t you quit kidding yourself and—”

Papyrus kissed him. 

Suddenly Sans felt his brother’s teeth pressed against his own, fierce, possessive magic sparking between them. Papyrus’ teeth parted and his tongue was suddenly inside Sans’ mouth, clumsily exploring, sliding across Sans’ own tongue, thoroughly catching him off guard. The magic in Sans’ pelvis manifested, and he could feel his shorts grow tighter against his erection.

Oh Stars, Papyrus tasted so good…

Fuck, fuck, fuck NO!

Sans pushed Papyrus away, gasping as he managed to get some space between them. 

“what the fuck?” Sans managed to pant, staring at Papyrus with shock.

Papyrus glared back at him belligerently, his crimson tongue snaking out to lick his teeth. 

“IF YOU ARE DISGUSTING, BROTHER, THEN SO AM I. AND HAVE BEEN FOR A LONG TIME NOW.”

Sans’ soul stuttered. 

Wait… what?

“wha… you…” 

“YES. ME. I HAVE LUSTED AFTER YOU FOR QUITE A WHILE SANS. SEE?”

Papyrus moved back slightly and gestured with his chin downward. Sans followed the motion with his eyes. There, at the crotch of Papyrus’ tight leather pants, was a soft glow and a very definite bulge.

Sans tried to swallow, but his mouth was too dry.

“no. that doesn’t matter. it’s still wrong,” he tried to argue, his voice hoarse even as he couldn’t tear his eyes away from what he was seeing. 

“YOU THINK I DON’T KNOW THAT?” Papyrus’ gaze darkened a bit, and Sans wondered briefly if Papyrus was recalling his own guilt. Then his brother’s eye lights sharpened with determination. “HOWEVER, UNLIKE YOU, BROTHER, I AM NOT IN THE HABIT OF DENYING MYSELF WHAT I DESIRE, ESPECIALLY NOW THAT I KNOW THAT YOU RETURN THE SENTIMENT.” 

As though to emphasize his point, Papyrus’ hand snaked down between Sans’ legs and cupped the bulge in his shorts, giving it a firm caress. Sans groaned, his hips canting up into the touch. Oh stars…

His mouth opened in an attempt to argue further, but his brain was entirely focused on the need he felt in his aching cock. 

Papyrus leaned down, his breath tickling what passed for Sans’ ear.

“SO WHAT DO YOU SAY, BROTHER?” he murmured. “SHOULD I HELP YOU WITH YOUR LITTLE… PROBLEM?”

He was going to hate himself later.

But he couldn’t deny himself now.

“oh stars, yes,” was all Sans could gasp.

“GOOD. THIS WON’T TAKE LONG” 

Papyrus withdrew, moving both hands down to the band of Sans’ shorts. He pulled it down, lifting it as he did so to reveal Sans’ dick, thick and heavy, laying against his pelvis and leaking precum down the shaft. 

Papyrus stared for a very long time. The enraptured look on his face caused Sans to flush with embarrassment. He shifted slightly on the sheets, fighting the urge to use his hands to hide himself. 

“c’mon, Boss. you gotta stare?” he grumbled, trying to cover for his uncharacteristic shyness. 

“YES,” came the blunt answer.

Papyrus’ eyes never left Sans as he removed his own pants, revealing his erect cock. Longer, larger, Sans watched as his brother palmed it, unable to pull his eyes away. His own magic twitched expectantly. 

After a few moments of this, Papyrus took Sans’ cock in hand, running it up and down along the shaft, slicking it further with the precum that had leaked from it. He paused briefly when Sans gave a choked moan, his eyes flicking up to his brother’s face with concern. Whatever he saw there, it reassured him enough to continue. Shifting his grip, he cradled Sans’ magic in his cupped fingers, then looped his thumb over his own dick as he pressed the two together.

Just the contact was amazing. Shaft to shaft, Sans could feel the low throb of his brother’s cock against the sensitive underside of his own, matching the beat of his soul. All Sans was aware of was that contact, his own panting breaths and the heat of his aroused magic coursing through his body. 

Papyrus began to move, thrusting slowly into the ring made by his hand, gliding against Sans in a glorious burst of pleasure that had them both groaning together. 

“fuck,” Sans gasped. It was not enough. “please, Pap… more…”

Obliging, Papyrus thrust harder and faster, building them up to a rhythm that had them both panting and moaning together. Sweat stood out on Sans’ overheated bones, and he could feel something winding tighter and tighter deep within the pit of his magic. 

“HAH~ SANS. ARE YOU CLOSE?” Papyrus asked, his voice low, hoarse and breathy, sending another pleasant shiver across Sans bones and nearly tipping him over the edge.

“stars, yes. i… yes…” was all he could manage. 

“THEN COME FOR ME… BROTHER.”

The eerie resemblance to his earlier fantasy had Sans climaxing almost immediately, his hips jerking into his brother’s hand as he gave a sharp cry. The extra motion must have pushed his brother over as well, because he was vaguely aware of Papyrus’ grunt above him, followed by a hot, wet spattering of what could only be cum following his own. 

Sans melted back into Papyrus’ bed, hazy and languid, feeling the cool sheets against his still warm bones. Holy fuck that had been so good. He stared up at his brother, pleasantly dazed, noting the soft, satisfied look on his brother’s face as he gazed back down at him. 

And then he was gone. Sans stared at the ceiling for some time, still trying to collect himself after… after…

oh shit.

His hand clutched at the bed sheet beside him. 

What had they done? What had HE done? This was wrong, this was…

“SANS. I CAN TELL FROM OVER HERE YOU’RE THINKING TOO MUCH. QUIT IT.” 

Sans’ eyes jerked to his Papyrus, who was standing once more at the foot of the bed with the basin in hand, having apparently gone to get some fresh water and a new cloth. He noticed that Papyrus had changed into pajama pants and a tank top, discarding his likely soiled clothes. 

“i… Papyrus, i…”

“SHUT UP.”

Kneeling down, Papyrus carefully and methodically used the cloth to wash Sans off, making sure to leave every last bit of him clean and fresh. The cloth felt good on his bones, and Sans couldn’t help but let himself submit to the care, secretly enjoying being coddled by one of the Underground’s fiercest. 

After washing him off, Papyrus climbed into bed with him, pulling him close and drawing the blankets up over them both. 

“Papyrus. maybe i shouldn’t…”

“DON’T RUIN THIS BONEHEAD.” Papyrus grumbled affectionately. “I… KNOW WE HAVE THINGS TO DISCUSS, BUT CAN WE WAIT TILL MORNING TO DO SO?”

Sans looked up into Papyrus’ face, reading the silent plea, despite the grim expression and serious eye lights. 

He never could resist any heartfelt request his bro made, could he?

“sure bro. see you in the morning.”


End file.
